The first Palestinian murder of an Israeli in the West Bank since 2011 and Israel’s first fatal air strike in Gaza since a November cease-fire today show the challenge Secretary of State John Kerry faces in overcoming Israel's emphasis on security over peace.

"Today we struck at one of those involved in the criminal firing of rockets at Eilat,” said Israeli Prime Minister Benjamin Netanyahu, referring to the assassination of suspected jihadist Haitham al-Meshal in Gaza. In addition, he vowed to respond to the murder of Eyvatar Borovsky, a father of five who was on his way to a theater rehearsal when a Palestinian stabbed him at a major junction near Nablus. “We will act, and are acting, in order to defend Israeli citizens."

Israeli settlers also took it upon themselves to retaliate for the murder of Mr. Borovsky, reportedly setting Palestinian fields and orchards on fire and attacking a mosque and two buses of Palestinian schoolgirls. A study last year by Israeli human rights group Yesh Din found that such retaliatory attacks result in an indictment only 9 percent of the time, angering Palestinians; Israel’s new justice minister, Tzipi Livni, has vowed to rein in such attacks.

Any increased friction with Gaza due to today's air strike is unlikely to derail any immediate peacemaking moves because Hamas has been excluded from US peacemaking efforts due to its refusal to give up armed struggle. And while settlers have outsized influence on the Israeli government, and many argue that concessions will pave the way for more terror, others say today’s killing only underscores the urgent need for a resolution to the Israeli-Arab conflict.

Secretary Kerry’s Middle East peace efforts got an important boost yesterday when Arab leaders in Washington agreed to soften the 2002 Arab Peace Initiative, which Israel had rejected. Qatari Prime Minister Hamad bin Jassim al-Thani, speaking after an Arab League delegation met with Kerry, said that they would normalize ties with Israel without requiring it to withdraw from the entire West Bank and East Jerusalem; instead, some “minor,” mutually agreed land swaps with a future Palestinian state would be acceptable.

A 'down payment' on peace?

Kerry has taken three trips to Israel since assuming office, making a concerted effort to jumpstart Israeli-Palestinian peace talks that have been suspended since 2010. Among his initiatives was an effort to revive the 2002 Arab peace plan, which Saudi Arabia had put forward during one of the most intense periods of the second Palestinian uprising, or intifada.

For years, Mr. Baskin says, Israel had pressed the Arab League on this point, asking, “Why do you have to be more Palestinian than the Palestinians?”

“This is a sense that they’re listening and they’re responding to it,” he says.

Inbar of Bar Ilan University suggests that part of the motivation may be a shared concern about Iran’s nuclear program, and a desire to make sure that the more “minor” issue of the Palestinians be settled so as not to overshadow the Iranian threat.

Settler: 'If you try to speak with them, you lose'

But at least some Israeli settlers see a connection between the increased US overtures to Palestinians and the broader Arab community, and a rise in violent activities.

“History tell us that every time that the United States or Israel sits with the Palestinians about [establishing] a state, about a move of Jewish people from Judea and Samaria, every time it creates a murder and killing and terror. This is the history of the area,” says Yigal Dilmoni, deputy CEO of the Yesha Council, an umbrella group that represents Israeli settlers. “If you fight the terror, you win. If you try to speak with them, you lose.”

A recent poll shows Palestinians to be far less supportive of violence against Israeli targets than after the November conflict between Israel and Hamas. Now, less than a third of Palestinians support military operations against Israel, down from 50.9 percent in December 2012, according to a poll released April 10 by the Jerusalem Media and Communications Centre. Likewise, support for rocket attacks from Gaza has dropped to 38.4 percent from 74 percent.

Today’s attack, the first fatal attack on Israelis since the March 2011 murder of the Fogel family, took place at Tapuah Junction, which is still guarded by the Israeli army even though the nearby checkpoint was removed several years ago as part of Mr. Netanyahu’s initiative to boost the Palestinian economy and quality of life. Israel identified Salam al-Zaghal of Tulkarem as the suspected attacker, who was taken into custody.

The Palestinian Mujahideen movement issued a statement praising today’s attack as a “natural response to the occupation’s aggression and its continuous attacks on all things Palestinian in the West Bank,” according to a translation by the Times of Israel.

Assaf Pney-El, a friend of Borovsky who worked with him on a sitcom about living in the settlements called “How did I meet Ahmed?,” says his theater ensemble is already thinking of how to carry on the legacy of their fellow actor, who used to carry a pair of googley-eyes in his hand and make a face with his finger for a nose.

“He took life with a smile, with a laugh,” says Mr. Pney-El. “That was his way to cope with things.”